Photos: Code machines at Bletchley Park

Nema cryptography device

One of the world's largest collections of Enigma cipher machines--famous for being used by the Nazis to protect communications during World War II--is to go on display at Bletchley Park in the U.K.

The Enigma electromechanical rotor machines were invented by a German engineer at the end of WWI and from the 1920s were used to encrypt and decrypt commercial, military, and government messages in many countries.

Enigma and other vintage cipher machines from across the world will be on display at Bletchley Park on the weekend of September 5-6, to coincide with the annual reunion of Allied codebreakers who had been based there and who cracked the Enigma code used by the German military, allowing allied commanders to predict and counter the movements of the Nazis.

More than 70 machines have been gathered from museums and private and government collections for the Enigma display at Bletchley--including devices from the U.K.'s Government Communications Headquarters, the National Cryptologic Museum in the U.S., and military museums elsewhere in Europe.

It will be the first time some of the machines have ever been seen in public in the U.K., such as the Swiss K model machine, which was used by the Swiss government to protect military and diplomatic messages.

The Swiss became concerned about the security of communications protected by the model K machine and from 1942 began designing a new cipher machine, called the New Machine (Nema). The Nema, seen here, remained in use in Switzerland from 1947 to 1963.

Portex machine

The eight-rotor Portex machine is a British made model that was dubbed a "super Enigma" machine. This compact but heavy device was mainly used to protect secret service communications in the 1940s and 1950s.

T244 machine

During WWII the Germans made the T244 machine and shipped it to Japan to allow their ally to protect its communications. Only a few of the machines made it to the Japanese high command, with most being intercepted or destroyed by Allied forces en route.

C36 cipher machine

This C36 cipher machine was used to protect official communications in France. The C36's code was broken quite easily by the Nazis in WWII, who used it to their advantage as their army swept across France in 1940.

M209 machine

The M209 machine was used by U.S. military during WWII and the Korean and Vietnam wars, with about 140,000 of the devices being built. The machine was made after the U.S. rejected the earlier C36 cipher machine used by the French as being too weak.